service add and service list

[masnax]

Closed the old PR to start fresh.

Adds two new commands:

• microcloud service list will list the cluster members for every installed service, or report if it is not initialized. This will effectively be the same as calling all of the following in succession:

lxc cluster list
microcloud cluster list
microceph cluster list
microovn cluster list

The information shown will be the name, address, dqlite role, and current status of each member.

• microcloud service add will try to setup MicroOVN and MicroCeph on all existing MicroCloud cluster members, optionally setting up storage and networks for LXD. This is useful if MicroOVN or MicroCeph was at one point not installed on the systems and skipped during microcloud init. LXD and MicroCloud itself are required to already be set up.
  Thanks to Reuse existing MicroCeph and MicroOVN clusters #259 we can also try to re-use a service that partially covers existing MicroCloud cluster members. So if a MicroCloud is set up without MicroCeph, and then the user manually configures MicroCeph to partially cover the cluster, the user can then use microcloud service add to further configure MicroCeph to work with MicroCloud, and set up storage pools for LXD.

[roosterfish]

Still looking very good, only a few smaller comments.